Some quick responses!
I would recommend 300pts as a starting point, which must include at least one 'elite'. Make sure you choose enough captains so you can activate everything with 2 or 3 activations. The simplest scenario we play is as follows:
Select forces. 300-500pts is a small game. I wouldn't recommend much bigger to begin with!
Lay out scenery on the table, but don't deploy figures yet. Draw a stone from the initiative pool - that player can now deploy his figures. Once he has deployed, the second player may immediately deploy figures at least 18" from his opponent. Continue with the first turn by drawing the next initiative counter.
The winner is the first person to kill more than half his opponents Elites.
I would recommend you try empire vs Devanu first as the delgon are a little trickier to get the hang of and you need to take care with force selection.
A game should take less than an hour generally, but can if course vary a lot!
Command stat is not always used at the moment, but is in there to be future-proof against abilities that might need it... Ignore it for the moment if the model doesn't have any leadership abilities.
Correct, a model gets one combat action per turn, either to attack or support. That action is lost if it is attacked first.
Models can most definitely kill each other in the same turn!
Font is Rennais-ital. Let me know if you have difficulty finding it.
I hope those responses help